Granules comprising an active substance

ABSTRACT

The present invention relates to granules comprising an active substance, obtained by spray-drying an emulsion comprising said active substance, solid particles, water and a water-soluble biopolymer having a molecular weight below 100 KDa. The invention further relates to a process for obtaining such granules and to products containing them.

TECHNICAL FIELD

The present invention relates to granules comprising an activesubstance, obtained by spray-drying an emulsion comprising said activesubstance, solid particles, water and a water-soluble biopolymer havinga molecular weight below 100 KDa. The invention further relates to aprocess for obtaining such granules and to products containing them.

PRIOR ART

Spray-drying is a well known technique for the encapsulation of flavoursand fragrances. Spray-dried granules are commonly prepared from anemulsion that is sprayed into a drying chamber. The emulsion typicallycomprises an active substance such as a flavour or a fragrance, acarrier and an emulsifier.

Most of the time, biopolymers with surface active properties, such asfor example gum arabic, modified starches, modified cellulose, gelatine,alginates or even proteins such as albumin or beta-globulin, are used ascarriers.

For example, US 2009/0253612 describes a spray-dry encapsulation processfor flavour or fragrance comprising drying an aqueous emulsioncontaining the oil to be encapsulated, modified starch and phosphatesalts.

When other types of carriers are used at least one emulsifier is used inaddition to the carrier. For example, Hidefumi et al., Innovative FoodScience & Emerging Technologies, 2 (2001), pp. 55-61, discloses aprocess for the microencapsulation of emulsified ethyl butyrate byspray-drying using maltodextrin as carrier and gum arabic as emulsifier.

A number of emulsion parameters influence the quality of the spray-driedsolid granules. The flavour or fragrance load in the granules, which isessential to achieve satisfying perceived intensity of the activesubstance in the final application depends in particular on theencapsulation yield which is defined as the amount of flavour orfragrance actually encapsulated in the granules, compared to thetheoretical amount that could be present if no flavour or fragrance waslost during the spray-drying process.

It is therefore desirable to provide granules obtained from emulsionshaving a high proportion of droplets of active substance and to limit asmuch as possible the loss of active substance, especially when it is avolatile active substance, during the drying step of the process.

Another important parameter of the emulsion to be spray-dried is thedispersion of the active substance in the aqueous phase. It wouldtherefore be advantageous to provide a system allowing a good dispersionof the active in the carrier and water.

The behaviour of the spray-dried granules when they are re-dissolved inwater also determines their quality. It is firstly desirable that thegranules have a good dispersion in water, so as to form a clearsuspension or solution. Secondly, the way the granules are capable ofreleasing the active substance to the headspace when they are dissolvedin water is also an essential characteristic of spray-dried granules. Aparticularly advantageous release profile is that wherein the release ofthe active substance is to maintained and controlled for a long period.

It would therefore be desirable to provide a new encapsulation processfor producing granules in which a high active substance load is achievedin the dry granules even with volatile substances, the obtained granulesforming clear solutions or suspensions when redispersed in water andreleasing in a suitable way the active substance to the headspace whendissolved in water.

It would further be useful to avoid the presence of polymericemulsifiers in the spray-dried emulsion.

To the best of our knowledge none of the spray-dried granules describedin the prior art solves these problems.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1: Aspect of dispersion of Granules B, C and D during the first 2hours after re-dispersion of the granules in water.

FIG. 2: Release profile of limonene in the headspace above there-dispersions in water of Granules C (diamonds) and Granules D(circles).

SUMMARY OF THE INVENTION

Accordingly, the invention relates to a process for preparing granules,the process comprising the steps of:

a) preparing an emulsion comprising

-   -   i. an active substance;    -   ii. a water soluble biopolymer having a molecular weight below        100 KDa and devoid of emulsifying properties;    -   iii. solid particles that are insoluble in water; and    -   iv. water;        b) spray-drying the emulsion obtained in step a) so as to obtain        granules.

In another aspect, the invention relates to spray-dried granulescomprising

-   i. an active substance;-   ii. a water soluble biopolymer having a molecular weight below 100    KDa and devoid of emulsifying properties; and-   iii. solid particles that are insoluble in water.

In a further aspect the invention relates to a consumer productcomprising the granules of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The present inventors have surprisingly discovered that when an emulsionintended to be spray dried is prepared with solid particles instead of asurfactant or polymeric emulsifier, the active substance loss during thedrying step is low, even if the active substance is volatile, such asflavours or fragrance compounds. The proportion of active substancedroplets in such emulsion can be high, so that high loads of activesubstance in the final granules can be obtained. It was alsosurprisingly discovered that the release of the perfume or fragrancefrom the granules of the invention is particularly advantageous, becausea long-lasting release of the active to the headspace is observed whenthe granules are re-dispersed in water.

In the first step of the process of the invention an emulsion isprepared comprising

-   i. an active substance;-   ii. a water soluble biopolymer having a molecular weight below 100    KDa and devoid of emulsifying properties;-   iii. solid particles that are insoluble in water; and-   iv. water.

The active substance can be an ingredient alone or a mixture of activeingredients. Preferably, the active substance comprises at least 90% byweight, relative to the total weight of the active substance, ofcompounds having a logP of at least 1, more preferably it comprises atleast 90% by weight of ingredients having a logP of at least 2. Evenmore preferably, the active substance comprises at least 99% by weight,relative to the total weight of the active substance, of ingredientshaving a logP of at least 1, most preferably it comprises at least 99%by weight of ingredients having a logP of at least 2. For the purpose ofthe present invention logP is defined as the calculated logP as obtainedby calculation using the EPI suite v3.10, 2000, U.S. EnvironmentalProtection Agency.

In a preferred aspect of the invention, the active substance is selectedfrom flavours and fragrances. For the purpose of the present invention,the terms “flavour or fragrance” encompass flavour or fragranceingredients or compositions of current use in the flavour and/orfragrance industry, of both natural and synthetic origin. It includessingle compounds and mixtures. Specific examples of such flavour orfragrance ingredients may be found in the current literature, e.g. inFenaroli's Handbook of flavour ingredients, 1975, CRC Press; SyntheticFood adjuncts, 1947 by M. B. Jacobs, edited by Van Nostrand; or Perfumeand Flavor Chemicals by S. Arctander, 1969, Montclair, N.J. (USA). Manyother examples of current flavouring and/or perfuming ingredients may befound in the patent and general literature available. The flavouring orperfuming ingredients may be present in the form of a mixture withsolvents, adjuvants, additives and/or other components, generally thoseof current use in the flavours and fragrance industry.

“Flavouring ingredients” are well known to a person skilled in the artof aromatising as being capable of imparting a flavour or taste to aconsumer product, or of modifying the taste and/or flavour of saidconsumer product, or yet its texture or mouthfeel.

By “perfuming ingredients” it is understood here compounds which areused as active ingredients in perfuming preparations or compositions inorder to impart a hedonic effect when applied to a surface. In otherwords, such compounds, to be considered as being perfuming ones, must berecognized by a person skilled in the art of perfumery as being able toimpart or modify in a positive or pleasant way the odor of a compositionor of an article or surface, and not just as having an odor. Moreover,this definition is also meant to include compounds that do notnecessarily have an odor but are capable of modulating the odor of aperfuming composition, perfumed article or surface and, as a result, ofmodifying the perception by a user of the odor of such a composition,article or surface. It also contains malodor counteracting ingredientsand compositions. By the term “malodor counteracting ingredient” we meanhere compounds which are capable of reducing the perception of malodor,i.e. of an odor that is unpleasant or offensive to the human nose bycounteracting and/or masking malodors. In a particular embodiment, thesecompounds have the ability to react with key compounds causing knownmalodors. The reactions result in reduction of the malodor materials'airborne levels and consequent reduction in the perception of themalodor.

Accordingly, in an embodiment, the active substance comprises at least 5wt. %, preferably at least 10. %, preferably at least 20%, morepreferably at least 30% and most preferably at least 40% of chemicalcompounds having a vapour pressure of at least 0.007 Pa at 25° C.,preferably at least 0.1 Pa at 25° C., more preferably at least 1 Pa at25° C. and most preferably at least 10 Pa at 25° C., all percentagesbeing defined by weight relative to the total weight of the activesubstance. Compounds meeting these criteria are generally regarded ashaving a volatile character and therefore have an odor or flavour. Themethod of the present invention therefore allows efficient encapsulationof high amounts of volatile ingredients. In a preferred embodiment ofthe invention, the active substance does not comprise any compound thatremains odorless due to a volatility below any of the above-mentionedthresholds.

For the purpose of the present invention the vapour pressure isdetermined by calculation. Accordingly, the method disclosed in “EPIsuite”; 2000 U.S. Environmental Protection Agency, is used to determinethe value of the vapour pressure of a specific compound or component ofthe active substance.

The amount of active substance in the emulsion is preferably comprisedbetween 5 and 67% by weight, more preferably between 10 and 40% byweight, relative to the total weight of the emulsion. This concentrationcorresponds to a concentration of the active substance of from 10 to90%, more preferably from 15 to 60% by weight, relative to the totalweight of the granules (dry weight).

Any water soluble biopolymer with a molecular weight below 100 KDa anddevoid of emulsifying properties can be used for the purpose of theinvention.

A “water soluble biopolymer” is intended for the purpose of the presentinvention as encompassing any biopolymer which forms a one-phasesolution in water. Preferably, it forms a one phase solution whendissolved in water at concentrations as high as 20% by weight, morepreferably even as high as 50% by weight. Most preferably it forms a onephase solution when dissolved in water at any concentration.

As “biopolymer devoid of emulsifying properties”, it is intended for thepurpose of the present invention polymers that are not surface activeand are devoid of barrier and emulsifying properties. Suitablebiopolymers devoid of emulsifying properties are soluble in water andare devoid of hydrophobic groups. Examples of biopolymers that areconsidered as having emulsifying properties and that are preferablyexcluded comprise gum Arabic, gelatine, modified starch such asoctenylsuccinated starch E1450 (Capsul™ Hicap™, Puritygum™, Emcap™etc.), modified cellulose such as ethylcellulose, hydroxypropylcelluloseor hydroxypropylmethylcellulose. Such polymers are avoided because theywould affect the particular release profile of volatiles from thegranules of the present invention.

Preferred water soluble biopolymers are biopolymers likepolysaccharides, oligosaccharides and disaccharides. Preferredpolysaccharides are starch hydrolysates with a dextrose equivalent above2 and most preferred ones are selected from dextrins, maltodextrins andcorn-syrup. The most preferred biopolymer for use in the presentinvention is maltodextrin.

It is also particularly advantageous to use water soluble biopolymerswhich do not comprise any chemical substitution, meaning that the watersoluble biopolymer has not been chemically (i.e. artificially) modified.

The water soluble biopolymer is preferably used in an amount of from 10to 70% by weight, more preferably from 30 to 55% by weight, relative tothe total weight of the emulsion. These concentrations are defined so asto maintain the viscosity of the emulsion below 400 Pa, which is apreferred range of viscosity in spray-drying processes.

The solid particles used in the emulsion are defined as any solidparticle that is insoluble in water. A particle is considered asinsoluble in water if its solubility is lower than 0.5% by weight.

Preferred particles are those having an average diameter of at most 3μm, more preferably of at most 500 nm.

Preferred solid particle types include the following:

-   -   silicon oxides, such as silica (e.g. colloidal silica such as        that sold under the tradename Klebosol® by AZ Electronic        Materials) or silicates (e.g. synthetic silicate such as that        sold under the tradename Laponite® by Rockwood Additives);    -   metal oxides, hydroxides, salts of inorganic or organic acids        and their mixtures (e.g. TiO₂, FeO, Fe(OH)₂, FeCO₃; MgO,        Mg(OH)₂, MgCO₃, Mg₃(PO4)₂; CaCO₃, CaSO₄, Ca₅(PO4)₃(OH),        Ca₃(C₆H₅O₇)₂);    -   silver nanoparticles;    -   magnesium and aluminium silicates (clays);    -   latexes;    -   dietary fibers such as microcrystalline cellulose, lignin and        chitin;    -   cells (e.g. yeast cells) or fragments thereof;    -   humic acid;    -   enteric polymers (such as for example Eudragit® FS 30 D and        Eudragit® L 100-55 from Evonik); and    -   crystals of fats or fatty acids.

Mixtures of such particle types can also be used. More preferably, thesolid particle is selected from

-   -   silicon oxides, such as silica (e.g. colloidal silica such as        that sold under the tradename Klebosol® by AZ Electronic        Materials) or silicates (e.g. synthetic silicate such as that        sold under the tradename Laponite® by Rockwood Additives);    -   metal oxides, hydroxides, salts of inorganic or organic acids        and their mixtures (e.g. TiO₂, FeO, Fe(OH)₂, FeCO₃; MgO,        Mg(OH)₂, MgCO₃, Mg₃(PO4)₂; CaCO₃, CaSO₄, Ca₅(PO4)₃(OH),        Ca₃(C₆H₅O₇)₂);    -   silver nanoparticles;    -   cells (e.g. yeast cells) or fragments thereof; and    -   dietary fibers such as microcrystalline cellulose, dextins,        lignin and chitin.

Most preferably, the solid particle is silica (e.g. colloidal silicasuch as that sold under the tradename Klebosol® by AZ ElectronicMaterials).

In a preferred aspect of the invention, the active substance ishydrophobic, as defined by a logP above 1, more preferably above 2, andthe solid particle is hydrophilic, i.e. it disperses easily in water toform a homogeneous suspension of particles. Preferably, in the emulsion,the particle will form with the oil and the water a contact angle θ≦90°,more preferably 10°≦θ≦90°. The contact angle θ is the three-phasecontact angle, measured through the aqueous phase, that is made by aninterface of water and oil on the particle's surface. Practically, whenthe contact angle is comprised within the above range the particlesucceeds in making an oil in water emulsion. It is well-known in thefield of colloids that the contact angle is a quantification of thewettability of the particles at an interface oil/water. A more detaileddefinition of the contact angle can be found in Dickinson, E., Use ofnanoparticles and microparticles in the formation and stabilization offood emulsions, Trends in Food Science & Technology (2011).

The relative ratio of solid particles, relative to the active substanceis preferably comprised between 1:1 and 1:30. In another preferredembodiment, the solid particles are present in an amount of from 0.1 to30%, preferably from 0.5 to 30% more preferably from 1 to 16% by weight,relative to the total weight of the emulsion.

In a preferred aspect of the invention, the amount of water in theemulsion is comprised between 20 and 80% by weight, relative to thetotal weight of the emulsion.

The emulsion may also contain optional ingredients. It may in particularfurther contain an effective amount of a fireproofing or explosionsuppression agent. The type and concentration of such agents inspray-drying emulsions is known to the person skilled in the art. Onecan cite as non-limiting examples of such fireproofing or explosionsuppression agents inorganic salts, C₁-C₁₂ carboxylic acids, salts ofC₁-C₁₂ carboxylic acids and mixtures thereof. Preferred explosionsuppression agents are, salicylic acid, acetic acid, propionic acid,butyric acid, isobutyric acid, valeric acid, caproic acid, citric acid,succinic acid, hydroxysuccinic acid, maleic acid, fumaric acid, oxylicacid, glyoxylic acid, adipic acid, lactic acid, tartaric acid, ascorbicacid, the potassium, calcium and/or sodium salts of any of theafore-mentioned acids, and mixtures of any of these.

Other optional ingredients include antioxidants, preservatives,colorants and dyes.

The emulsion can be formed using any known emulsifying method, such ashigh shear mixing, sonication or homogenization. Such emulsifyingmethods are well known to the person skilled in the art.

Preferably the emulsion is free of emulsifiers.

The droplet size d(v,0.9) of the emulsion is preferably comprisedbetween 0.5 and 15 μm, more preferably between 0.5 and 10 μm.

In step b), the emulsion is spray-dried so as to obtain granules.

The emulsion is first subjected to a spraying step during which theemulsion is dispersed in the form of drops into a spraying tower. Anydevice capable of dispersing the emulsion in the form of drops can beused to carry out such dispersion. For instance, the emulsion can beguided through a spraying nozzle or through a centrifugal wheel disk.Vibrated orifices may also be used.

In one aspect of the invention the emulsion is dispersed in the form ofdrops into a cloud of powdering agent present in the dry tower. Suchtype of process is for example described in details in WO2007/054853 orin WO2007/135583.

For a specific formulation, the size of the granules is influenced bythe size of the drops that are dispersed into the tower. When a sprayingnozzle is used for dispersing the drops, the size of such drops can becontrolled by the flow rate of an atomising gas through the nozzle, forexample. In the case where a centrifugal wheel disk is used fordispersal, the main factor for adjusting droplet size is the centrifugalforce with which the drops are dispersed from the disk into the tower.The centrifugal force, in turn, depends on the speed of rotation and thediameter of the disk. The feed flow rate of the emulsion, its surfacetension and its viscosity are also parameters controlling the final dropsize and size distribution. By adjusting these parameters, the skilledperson can control the size of to the drops of the emulsion to bedispersed in the tower.

Once sprayed in the chamber, the droplets are dried using any techniqueknown in the art. These methods are perfectly documented in the patentand non-patent literature in the art of spray-drying. For example,Spray-Drying Handbook, 3^(rd) ed., K. Masters; John Wiley (1979),describes a wide variety of spray-drying methods.

The process of the present invention may be performed in anyconventional spraying tower. A conventional multi-stage drying apparatusis for example appropriate for conducting the steps of this process. Itmay comprise a spraying tower, and, at the bottom of the tower, afluidised bed intercepting partially dried granules after fallingthrough the tower.

The amount of flavour or fragrance lost during the spray drying step ispreferably below 15%, more preferably below 10%, most preferably below5%, these percentages being defined by weight, relative to thetheoretical amount that would be present in the granules if there wasabsolutely no flavour or fragrance lost during the spray-drying step.

The spray-dried granules of the present invention typically comprise

-   i. an active substance;-   ii. a water soluble biopolymer having a molecular weight below 100    KDa and devoid of emulsifying properties;-   iii. solid particles that are insoluble in water; and-   iv. water.

All components of the granules are as defined above.

The granules of the invention may also comprise residual amounts ofwater, but typically less than 15%, preferably less than 10%, morepreferably less than 2% by weight, relative to the total weight of thegranules.

Preferably such granules are obtainable and/or obtained by the processdescribed in any of the above embodiments of the invention.

In a preferred aspect of the invention the size of the granules istypically of at least 10 μm, preferably at least 20 μm. Depending on theprocess used for spray-drying, in particular when a powdering agent ispresent in the drying tower, as described above, the dry granules canhave an average size of up to 300 or even up to 750 μm. In a preferredembodiment of the invention, the average size of the granules is atleast 5 times larger than the average size of the oil droplets in theemulsion.

In another aspect, the invention relates to a consumer productcomprising the to granules of the invention. Preferably such product isa flavoured or fragranced product.

Preferably, the flavoured product is a food product. The consumerproduct of the invention preferably is a particulate or powderyflavoured or fragranced product. In such a case, the granules of theinvention may easily be added thereto by dry-mixing.

In a preferred aspect of the invention, the food product is selectedfrom the group consisting of an instant soup or sauce, a breakfastcereal, a powdered milk, a baby food, a powdered drink, a powderedchocolate drink, a spread, a powdered cereal drink, a chewing gum, aneffervescent tablet, a cereal bar, and a chocolate bar. The powderedfoods or drinks may be intended to be consumed after reconstitution ofthe product with water, milk and/or a juice, or another aqueous liquid.

In an embodiment the fragranced product is a powdery product. Preferablyit is a powder or a tablet detergent, a deodorant or an antiperspirant.In another embodiment, it is a body care product and most preferably itis a deodorant or an antiperspirant.

The granules of the present invention have the advantage of being welldispersed in aqueous media and in particular in consumer product basescomprising water.

EXAMPLES

The invention will now be described in further detail by way of thefollowing examples.

Example 1 Preparation of Granules According to the Invention

Emulsion A was prepared having the following ingredients:

TABLE 1 Composition of Emulsion A Parts by Ingredient weight [%]Flavour¹⁾ 17.65 Water soluble biopolymer²⁾ 41.17 Solid particles³⁾ 3.17Citric acid 0.12 Antibacterial agent⁴⁾ 0.02 Water 37.87 Total 100¹⁾Lemon oil, origin: Firmenich SA, Geneva, Switzerland ²⁾Glucidex ® 18DE (Maltodextrin, origin: Roquette Frères) ³⁾Klebosol ® 30V25(suspension of colloidal silica), origin: AZ Electronic Materials⁴⁾Potassium sorbate and sodium benzoate.Lemon oil (30 g) was added to a dispersion of 18 g of Klebosol® in 52 gof distilled water containing the antibacterial agent. The pH wasadjusted to 3 by addition of citric acid. The to resulting mixture washomogenized using an ultrasonic probe in cold conditions (water bathwith ice). The average size of the oil droplets was visually checked bymicroscopy to be around 3 μm. The obtained emulsion was then blendedusing a propeller type mixer with 70 g of Glucidex®.Granules A were prepared by spray-drying Emulsion A using a Buchi MiniSpray-Dryer B-290, supplied by Büchi, Flawil, Switzerland, with an airinlet temperature set to 180° C. and a throughput set to 500 ml perhour. The air outlet temperature was of 90° C. The emulsion beforeatomization was at ambient temperature.The lemon oil content in the spray-dried granules was measured by LF-NMRusing the proper calibration. The encapsulation efficiency was estimatedby measuring the amount of oil in the granules and comparing with thetheoretical content that would be achieved without any loss during thespray-drying process. The amount of lemon oil lost was less than 5%, thefinal loading of lemon oil in the granules being about 28.4% by weight,relative to the total weight of the granules.

Example 2 Preparation of Granules with Modified Starch as Emulsifier(Comparative Example)

Emulsion B was prepared having the following ingredients:

TABLE 2 Composition of Emulsion B Parts by Ingredient weight [%]Flavour¹⁾ 15.00 Water soluble biopolymer²⁾ 31.50 Emulsifier³⁾ 3.50Antibacterial agent⁴⁾ 0.02 Water 49.98 Total 100 ¹⁾Lemon oil (origin:Firmenich SA, Geneva, Switzerland) ²⁾Glucidex ® 18 DE (Maltodextrin,origin: Roquette Frères) ³⁾Hi-Cap ®100 (modified starch), origin:National Starch ⁴⁾Potassium sorbate and sodium benzoate.Emulsion B was prepared using the same protocol as described in Example1, except that the solid particles were replaced by the emulsifier.The average size of the oil droplets was visually checked by microscopyand measured by granulometry (Malvern Nanosizer) to be almost the sameas for Emulsion A, i.e. about 3 μm.Granules B were prepared following the same protocol as described inExample 1.Also following the same protocol as in Example 1, the amount of lemonoil lost during the spray-drying process was measured. About 11% of theoil was lost, leading to a final oil loading in Granules B of about26.6% wt.The ratio solid material/active (oil) being comparable in both Examples1 and 2, the main difference between these two examples is the use ofsolid particles instead of a polymeric emulsifier. Comparison of thesetwo example shows that less flavor (lemon oil) is lost under similarconditions of formulation and process when the spray-dried emulsioncomprises a solid particle (silica) instead of an usual emulsifier(modified starch), which further results in an improved oil loading inthe spray-dried granules of the invention compared to the prior artones.The average size of the obtained spray-dried granules was about 50 μm,as estimated by microscopy.

Example 3 Preparation of Granules According to the Invention

Emulsion C was prepared having the following ingredients:

TABLE 3 Composition of Emulsion C Parts by Ingredient weight [%]Flavour¹⁾ 20.69 Water soluble biopolymer²⁾ 31.03 Solid particles³⁾ 1.86Citric acid 0.14 Antibacterial agent⁴⁾ 0.02 Water 46.26 Total 100¹⁾Lemon oil (origin: Firmenich) ²⁾Glucidex ® 18 DE (Maltodextrin,origin: Roquette Frères) ³⁾Klebosol ®30V25 (suspension of colloidalsilica), origin: AZ Electronic Materials) ⁴⁾Potassium sorbate and sodiumbenzoate.Emulsion C was prepared using the same protocol as in example 1, onlythe amount of each ingredient being different. Granules C were thenprepared by spray-drying of Emulsion C using the process described inExample 1.

Example 4 Preparation of Granules with Modified Starch as Emulsifier(Comparative Example)

For comparative study, Emulsion D was prepared having the followingingredients:

TABLE 4 Composition of Emulsion D Parts by Ingredient weight [%]Flavour¹⁾ 20.00 Water soluble biopolymer²⁾ 27.00 Emulsifier³⁾ 3.00Antibacterial agent⁴⁾ 0.02 Water 49.98 Total 100 ¹⁾Lemon oil (origin:Firmenich) ²⁾Glucidex ® 18 DE (Maltodextrin, origin: Roquette Frères)³⁾Capsul ™ (modified starch), origin: National Starch ⁴⁾Potassiumsorbate and sodium benzoate.Emulsion D was prepared using the same protocol as in example 2, onlythe amount of each ingredient being different. Granules D were thenprepared by spray-drying Emulsion D using the process disclosed inExample 1.

Example 5 Re-Dispersion of the Granules of the Invention in Water

Based on the lemon oil loading of Granules B, C and D, the granules werere-dispersed in demineralised water using magnetic stirrer to reach afinal concentration of lemon oil of 0.005% by weight, relative to thetotal weight of the dispersion.The turbidity of the obtained dispersion was assessed visually.Surprisingly the re-dispersion in water of the granules of the invention(Granules C, stabilized by solid particles) led immediately to a clear,almost transparent solution. By comparison the solutions were opticallyturbid when comparative Granules B and D were re-dispersed in water. Theaspect of the dispersions remained the same for two hours (see FIG. 1).The ability of the capsules of the present invention to re-dispersequickly in water to provide a clear dispersion is very advantageous, inparticular in applications where transparency is generally needed, forexample in beverages.

Example 6 Volatile Compound Release from Granules of the Invention

Granules C and D were re-dispersed in demineralised water to reach afinal concentration of lemon oil of 0.5% by weight relative to the totalweight of the dispersion in both cases. The release profile of limonene,the main component of lemon oil, was measured over time in the headspaceabove each solution in identical conditions of analysis. Staticheadspace was performed at 32° C. as a reference for the concentrationin limonene (P₀′). Headspace measurements were performed in dynamicconditions under 45 ml/min nitrogen flow at 32° C. (P′). Measurementswere performed in triplicate.

As shown in FIG. 2, the limonene release from Granules D (comparative)is an almost linear decrease of limonene concentration in the gas as afunction of time. In comparison, for Granules C (invention) a strongdecrease is observed for the first 10 minutes, followed by a stronginflexion point and a more constant concentration of limonene in the gasfor the 10 hours of the analysis.The consequence of this difference in release profile it that afterabout seven hours, the amount of limonene in the headspace abovere-dispersion of Granules D (comparative) is lower than that in theheadspace above re-dispersion of Granules C (invention). The controlledrelease from the granules of the invention, thus leads to a long-lastingeffect that is advantageous for flavours and for perfumery applicationssuch as antiperspirants or body care applications.

Example 7 Preparation of Granules from a Standard Pickering Emulsion(Comparative)

Emulsion E was prepared having the following ingredients:

TABLE 5 Composition of Emulsion E Parts by Ingredient weight [%]Flavour¹⁾ 30.00 Solid particles²⁾ 2.70 Citric acid 0.20 Antibacterialagent³⁾ 0.04 Water 67.06 Total 100 ¹⁾Lemon oil (origin: Firmenich)²⁾Klebosol ®30V25 (suspension of colloidal silica), origin: AZElectronic Materials) ³⁾Potassium sorbate and sodium benzoate.Emulsion E was prepared using the same protocol as described in Example1, except that the water-soluble biopolymer was not added.Granules E were then prepared following the same protocol as describedin Example 1. Also following the same protocol as in Example 1, theamount of lemon oil lost during to the spray-drying process wasmeasured. About 84.4% of the oil was lost, leading to a final oilloading in Granules E of about 4.69% wt.This example clearly shows the advantage of the present invention overspray-drying of emulsions stabilized by solid particles but containingno water-soluble biopolymer, such emulsions being unable to protectvolatile substances during the drying step.

Example 8 Preparation of Granules According to the Invention

Emulsion F was prepared having the following ingredients:

TABLE 6 Composition of Emulsion F Parts by Ingredient weight [%]Flavour¹⁾ 17.65 Water soluble biopolymer²⁾ 41.18 Solid particles³⁾ 0.41Citric acid 0.06 Antibacterial agent⁴⁾ 0.01 Water 40.69 Total 100¹⁾Lemon oil (origin: Firmenich) ²⁾Glucidex ® 18 DE (Maltodextrin,origin: Roquette Frères) ³⁾Natpure Cellgum (microcrystalline cellulose,origin: Sensient Technologies LCW) ⁴⁾Potassium sorbate and sodiumbenzoate.Emulsion F was prepared using the same protocol as in example 1, onlythe type of solid particles and the amount of each ingredient beingdifferent. Granules were then prepared by spray-drying of Emulsion Fusing the process described in Example 1.

Example 9 Preparation of Granules According to the Invention

Emulsion G was prepared having the following ingredients:

TABLE 7 Composition of Emulsion G Parts by Ingredient weight [%]Flavour¹⁾ 17.65 Water soluble biopolymer²⁾ 41.18 Solid particles³⁾ 1.65Citric acid 0.18 Antibacterial agent⁴⁾ 0.01 Water 39.34 Total 100¹⁾Lemon oil (origin: Firmenich) ²⁾Glucidex ® 18 DE (Maltodextrin,origin: Roquette Frères) ³⁾Laponite ®RD (synthetic layered silicate,origin: Rockwood Additives) ⁴⁾Potassium sorbate and sodium benzoate.Emulsion G was prepared using the same protocol as in example 1, onlythe type of solid particles and the amount of each ingredient beingdifferent. Granules were then prepared by spray-drying of Emulsion Gusing the process described in Example 1.

Example 10 Preparation of Granules According to the Invention

Emulsion H was prepared having the following ingredients:

TABLE 8 Composition of Emulsion H Parts by Ingredient weight [%]Flavour¹⁾ 17.65 Water soluble biopolymer²⁾ 41.18 Solid particles³⁾ 0.41Citric acid 0.06 Antibacterial agent⁴⁾ 0.01 Water 40.69 Total 100¹⁾Lemon oil (origin: Firmenich) ²⁾Glucidex ® 18 DE (Maltodextrin,origin: Roquette Frères) ³⁾Humic acid (origin: Fluka) ⁴⁾Potassiumsorbate and sodium benzoate.Emulsion H was prepared using the same protocol as in example 1, onlythe type of solid particles and the amount of each ingredient beingdifferent. Granules were then prepared by spray-drying of Emulsion Husing the process described in Example 1.

Example 11 Preparation of Granules According to the Invention

Emulsion I was prepared having the following ingredients:

TABLE 9 Composition of Emulsion I Parts by Ingredient weight [%]Flavour¹⁾ 17.65 Water soluble biopolymer²⁾ 41.18 Solid particles³⁾ 0.41Antibacterial agent⁴⁾ 0.01 Water 40.75 Total 100 ¹⁾Lemon oil (origin:Firmenich) ²⁾Glucidex ® 18 DE (Maltodextrin, origin: Roquette Frères)³⁾Eudragit ®L100-55 (Methacrylic acid - Ethylacrylate copolymer, origin:Evonik) ⁴⁾Potassium sorbate and sodium benzoate.Emulsion I was prepared using the same protocol as in example 1, onlythe type of solid particles and the amount of each ingredient beingdifferent. Eudragit®L100-55 was insoluble in water in the conditions ofemulsification. Granules were then prepared by to spray-drying ofEmulsion I using the process described in Example 1.

Example 12 Preparation of Granules According to the Invention

Emulsion J was prepared having the following ingredients:

TABLE 10 Composition of Emulsion J Parts by Ingredient weight [%]Flavour¹⁾ 17.647 Water soluble biopolymer²⁾ 41.176 Solid particles³⁾0.412 Sodium hydroxide 0.001 Antibacterial agent⁴⁾ 0.012 Water 40.752Total 100 ¹⁾Lemon oil (origin: Firmenich) ²⁾Glucidex ® 18 DE(Maltodextrin, origin: Roquette Frères) ³⁾Latex particles (crosslinkedcopolymer of Methylmethacrylate - methacrylic acid and1,4-bis(vinyloxy)butane, origin: Firmenich) ⁴⁾Potassium sorbate andsodium benzoate.Emulsion J was prepared using the same protocol as in example 1, onlythe type of solid particles and the amount of each ingredient beingdifferent. Latex particles were insoluble in water in the conditions ofemulsification. Granules were then prepared by spray-drying of EmulsionJ using the process described in Example 1.Examples 1, 3 and 8-12 demonstrate the wide variety of solid particleswhich can be used to in the preparation of emulsions such as describedabove, and which include, but are not limited to, silica,microcrystalline cellulose, Laponite®, Humic acid, Eudragit® and latexparticles.

1. A process for preparing granules, the process comprising the stepsof: a) preparing an emulsion comprising i. an active substance selectedfrom the group consisting of a flavour and a fragrance; ii. a watersoluble biopolymer having a molecular weight below 100 KDa and devoid ofemulsifying properties; iii. solid particles that are insoluble inwater; and iv. water; b) spray-drying the emulsion obtained in step a)so as to obtain granules.
 2. A process according to claim 1, wherein theactive substance comprises at least 90% by weight, relative to the totalweight of the active substance, of compounds having a logP of atleast
 1. 3. (canceled)
 4. A process according to claim 1 wherein theflavour is used in an amount of from 5 to 67% by weight, relative to thetotal weight of the emulsion.
 5. A process according to claim 1 whereinthe water soluble biopolymer is selected from polysaccharides,oligosaccharides and disaccharides.
 6. A process according claim 1wherein the water soluble biopolymer is used in an amount of from 10 to70% by weight, relative to the total weight of the emulsion.
 7. Aprocess according to claim 1 wherein the solid particles have an averagediameter of at most 3 μm.
 8. A process according to claim 1 wherein thesolid particles are selected from the group consisting of siliconoxides, such as silica or silicates such as for example the syntheticsilicate sold under the tradename Laponite® by Rockwood Additives; metaloxides, hydroxides, salts of inorganic or organic acids and theirmixtures (e.g. TiO₂, FeO, Fe(OH)₂, FeCO₃; MgO, Mg(OH)₂, MgCO₃,Mg₃(PO4)₂; CaCO₃, CaSO₄, Ca₅(PO4)₃(OH), Ca₃(C₆H₅O₇)₂); silvernanoparticles; magnesium and aluminium silicates (clays); latexes;dietary fibers such as microcrystalline cellulose, lignin and chitin;cells (e.g. yeast cells) or fragments thereof; humic acid; entericpolymers (such as for example Eudragit® FS 30 D and Eudragit® L 100-55from Evonik); and crystals of fats or fatty acids.
 9. A processaccording to claim 1 wherein the solid particles are silica particles.10. A process according to claim 1 wherein the solid particles are usedin an amount of from 0.1 to 30% by weight, relative to the total weightof the emulsion.
 11. A process according to claim 1 wherein the ratio ofsolid particles to active substance is ranging between 1:1 and 1:30. 12.Spray-dried granules comprising: i. an active substance; ii. a watersoluble biopolymer having a molecular weight below 100 KDa and devoid ofemulsifying properties; and iii. solid particles that are insoluble inwater.
 13. Spray-dried granules obtainable by the process according toclaim
 1. 14. A consumer product comprising the granules according toclaim
 12. 15. A consumer product according to claim 14, wherein saidproduct is a flavoured or fragranced product.
 16. A consumer productcomprising the granules according to claim
 13. 17. A consumer productaccording to claim 16, wherein said product is a flavoured or fragrancedproduct.